Mercury switch



y 15, 1930- P. K. CRAMBLET 1,770,479

MERCURY SWITCH Filed Jan. 5, 1927- [/V VE/V 70/? PM A. W

A TTORNE Y.

Patented July 15, 1930 UNITED STATES PAIENT OFFICE PAUL K. CRAMBLET, OF MILWAUKEE, WISCONSIN, ASSIGNOR TO TIME-O-STA'I. CON- I TBOLS COMPANY, OF ELKHAR'I', INDIANA, A CORPORATION OF MARYLAND.

MERCURY SWITCH Application filed January 5, 1927. Serial No. 159,061.

This invention relates in general to mercury switches and more particularly to mercury switches having two or more sets of electrodes, each set of electrodes having a body of mercury cooperable therewith.

One of the principal objects of the invention is to provide a mercury switch which embodies a plurality of sets of electrodes and a body of mercury cooperable with each set of electrodes and yet is comparatively inex' nsive to manufacture by reason of the particularly pointed out in the appended fact that a single outer envelope is employed and a single operation serves to effect the finalevacuation and gas filling in one tubu-.

lation while the advantages of entirely separate chambers for the mercury and electrodes are preserved.

Another important object is to provide a switch having these advantages and capacities'and which maybe made up in various types of switches which in particular may be readily made up in a mercury switch of the type embodying an outer envelope of soft glass and an inner tube or sleeve of hard glass which operatesto confine the zone of arcing to an arcing surface of hard glass located a point removed from the inner walls of the soft glass outer envelope.

In accordance with the present invention each set of electrodes and its body of mercury operate in a separate chamber provided therefor in the switch and the several chambers of the, switch are formed in a single outer envelope of the switch by means of a partition impervious to mercury but pervious to gas so that the air may be evacuated from both or all chambers and all chambers filled with gas in a single operation through a single sealing tip provided on but one of the chambers. In its broader aspects the invention proposes a novel circuit making and breaking device comprising two electrically separated switches in one envelope.

Other objects and advantages reside in certain novel features of the construction, arrangement and combination of parts which will be hereinafter more fully described and claims, reference being had to the accompanying drawings forming a part of this specification, and in which:

Figure 1 is a sectional view showing one type of switch embodying the invention.

ig. 2- is a view in central, vertical, longitudinal section illustrating another embodiment of the invention; and

Fig. 3 is .a sectional view on line 33 of Fig. 2.

Referring to the drawings and more particularly to Figure 1, the numeral 1 designates generally an outer envelope preferably of soft glass and having its interior divided up into chambers 2 and 3 by means of a solid disk-like partition 4. The partition 4 completely obstructs the interior opening of the envelope and is made of a material impervious to mercury but pervious to gas. In

tition completely prevents the passage of any mercury from the chamber 2 to the chamber 3 or vice versa. As shown in the drawings, this partition 4 is in the form of a solid disk and preferably is a disk of asbestos which is cemented or otherwise securely fastened to the tube. disk of asbestos or may be constructed of tightly wound asbestos tape to produce the solid or substantially solid disk structure. After the partition is made it is pushed into place through one end of the tube, which end is open at such time, and then a small quantity of glue, cement or any suitable adhesive is poured on thepartition around its periphery and impregnates it and adheres to the inner wall of the outer envelope around the partition to firmly secure thepartition in place. ,Thus the partition while presenting a strong and substantially rigid structure in the final assembly, is nevertheless porous with respect to air, hydrogen or otherinert as usually employed in mercury switches, ut entirely impervious to mercury. Into the chamber 2 electrodes 5 extend, the electrodes or their lead in wires being suitably sealed in the wall of the chamber 2 and coacting with a body 6 of mercury.

Into the chamber 3 electrodes 7 extend and are suitably sealed, the electrodes 7 coacting The partition 4, may be a solid with a body of mercury 8. The electrodes 5 and 7 are constituted of any suitable metal and preferably are made up of iron or other metal known in the art as having the properties rendering it will adapted for use in this connection. The air is evacuated from the chambers 2 and 3 through a single sealing tip 9 and through this same tip or tubulation 9 hydrogen gas is injected. Of course any suitable inert arc suppressing gas may be employed in lieu of hydrogen. Thus the single sealing tip or tubulation 9 serves for the evacuation and filling of both chambers and a single operation is involved. In Figure 1 of the drawing a second seal or tip is shown at 9 but this is not a tubulation employed for air evacuation and gas filling, but a simple seal. In making up the switch it is convenient to make up completely one end thereof leaving only the air evacuation and gas filling to be done. In other words, after the partition 4 is in place the electrodes 5 are sealed in, the tip 9 is formed, the mercury 6 introduced through the tip 9 and the tip 9 sealed. This operation is repeated for the chamber 3, except that after placing the mercury 8 in this chamber through the tip 9, air is evacuated and gas introduced through the tip or tubulation 9 before it is sealed.

In the form of the invention shown in Figures 2 and 3, a soft glass envelope 10 is provided and its interior divided into chambers 11 and 12 by means of a partition 13 similar to the partition 4, the partition 13 completely obstructing the internal opening of the envelope 10 and being constructed of solid or wound asbestos or other material impervious to mercury but porous and pervious to air, hydrogen or other gas, and being cemented or otherwise suitably secured to the envelope 10. In the chamber 11 a sleeve or tube 15 of hard glass, such as'pyrex or quartz, is disposed, and this sleeve 15 is mounted on a ring-like partition 16 interposed between the outer periphery of the tube 15 at one end of the tube and the adjacent portion of the inner periphery of the envelope 10. This partition 16 is constituted of asbestos and may be formed of a strip of asbestos tape wound to produce the annular or ring-like structure, the partition 16 being cemented or otherwise suitably secured to the envelope and to the tube. This arrangement provides a means for supporting the tube or sleeve 16 in substantially fixed position within the envelope 10 and yet the asbestos is sufliciently yielding or shock absorbing to prevent transmission of stresses, strains and shocks between the envelope 10 and the sleeve or tube 15.

As shown in the drawings, the tube 15 is open' ended. An electrode '17 extends in through and is suitably sealed in the envelope 10 at a'point between'the partition 16 and the partition 13 and this electrode 17 is then bent at right angles and extended through the tube to a point adjacent to but spaced from the somewhat flattened end 15 of the tube 15. An electrode 18 is provided and extends in through and is sealed in the end of the envelope 10 and terminates at a point between the outer periphery of the sleeve or tube 15 and the inner periphery of the envelope 10. A body of mercury designated at 19 is provided within the chamber 11 and this body of mcr cury in one position of the switch is a single continuous body in which the electrodes 17 and 18 are immersed whereby the mercury bridges the electrodes. In another position of the switch the mercury divides into two portions, one portion of the mercury being located within the tube 15 and within the space 17 defined between the partitions 16 and 13 and the other portion of the mercury being located in the space 16 around the outside of the tube 15 and on the opposite side of the partition 16 from the space 17*. It will be noted that in both positions of the switch the electrodes are immersed in mercury and it will be further noted that a mercury to mercury make and break is provided and occurs within the tube 15 on the relatively broad surface designated at 15. Thus the tube 15 serves to confine the arcing zone to a point spaced from the inner periphery or wall of the soft glass envelope against the deleterious effect of arcing.

In the chamber 12 a tube or sleeve 20 of hard glass such as pyrex or quartz is provided and is supported on an asbestos ring 21 similar to the partition 16. The tube 20 is identical in construction with the tube 15. The partition 21 defines spaces 20' and 21 Within the chamber 12, these spaces 20 and 21 corresponding to the spaces 16- and 17' respectively. An electrode 22 is provided in conjunction with the chamber 12 and extends in through and is sealed in the end Wall of the envelope 10 and in through the tube 20, the electrode 22 terminating within the tube 20 as shown. Similarly, an electrode 23 extends in through and is sealed in the envelope 10 and terminates within the space 20 and between the sleeve or tube 20 and the envelope 10. Abody of mercury, designated at 24, is provided within the chamber 12 and in the closed position of the switch provided in chamber 20 this body of mercury is one con tinuous body which immerses and bridges electrodes 22 and 23. In the other position of this switch the body of mercury divides into two portions separated from each other by the hard glass tube or sleeve 20 and thrpartition 21 but still immersing electrodes 23 and 23, respectively. It is to be noted in this instance, as in the previous one, a IIlQ!f.'H- ry to mercury make and break is had and 0tcurs on the relatively broad surface indicated at 20 and within the tube or sleeve 20. A single sealing tip or tubulation 25 is provided for evacuating the air from and filling both chambers 11 and 12 with gas and may be located to directly communicate with the chamber 12. However, since the partition 13 is pervious or porous to air and gas, the suction exerted through the tubulation is also exerted in the chamber 11 so that by a single operation and from the single tip 25 the air may be evacuated from both the chambers 11 and 12 and these chambers filled with gas. It is also to be noted that the partitions 16 and 21 do not resist this evacuation in any way since they also are porous or pervious to gas.

As shown in. Figure 2, the outer envelope 10 ma also have a seal or tip 26 at the end opposlte the tip 25, but the tip 26 is not em- I ployed for evacuating air or introducing gas ut is provided merely to carry out one mode of making the switch. When the switch in the chamber 11 is first made up complete except for "air evacuation and gas filling, the sealing tip 26 is provided to facilitate the introduction of mercury into chamber 11.

- Then after the switch in chamber 12 is made up the mercury is introduced through tubulation 25 and both chambers 11 and 12 are evacuated of air and filled with gas through this tubulation 25. However, if desired, the

assembly of the switches in chambers 11 and 12 may be such as to make the seal 26 unnecessary. This isalso-true of the seal 9 in the device shown in Figure 1.

Thus with both forms of the invention and with various types of switches the plurality of switch units may have the air exhausted from the chambers which house the same and may be filled with a suitable inert arc suppressing gas through a single sealing tip and in a single operation. This makes it possible and practical to have two electrically separated switches in a single envelope.

rality of switch chambers in such manner as" to electrically isolate the several chambers whil'e permitting the transfer of air and gas therebetween. In placing a mercury switch unit in each chamber and completing the sealing of all of the chambers except one, in sealing the latter chamber except for the provision of a single tubulation. in exhausting air from all of the chambers through said single tubulation, in filling all of the chambers through said tubulation and in sealing all said tubulations. The latter phases of the method in their broader aspect consist simply of exhausting air from all of the chambers and filling all of the chambers with gas through a single opening.

The invention claimed is:

1. A mercury switch comprising an envelope, a partition dividing the envelope into two non-communicating chambers, said partition being impervious to mercury but being porous or pervious to gas whereby the air may be evacuated from both chambers of the envelope and both chambers of the envelope may be'filled with gas from and through a single point on the envelope, electrodes in each chamber, and abody of mercury in each chamber and cooperable with the electrodes thereof.

2. A mercury switch comprising an envelope, a partition intermediately positioned in the envelope and dividing the same into two non-communicating chambers, said partition being. impervious -to mercury but being pervious to gas, and a single sealing tip on said envelope and communicating directly with one of the chambers and indirectly with the other chamber through said partition.

3. A mercury switch comprising an outer envelope of soft glass, a partition within the envelope and dividing the same into two non-- communicating chambers, said partition being impervious to mercury but being porous or pervious to gas, said partition completely obstructing the internal opening of ,the outer. soft glass envelope, a hard glass tube in each chamben an annular partition between one end of each tube and the outer soft glass envelope to support the tube on the envelope and divide the chamber into two compartments, electrodesin each compartment and a body of mercury in each chamber and immersing the electrodes thereof in all positions of the switch and serving to bridge the electrodes in one position of the switch but,

being divided into twoseparate ortions in another position of the switch, said mercury making and breaking within the tube. v

4. A mercury switch comprising an envelope, a solid disk-like partition of asbestos tightly fitted in the envelope intermediate its ends and completely obstructing the internal opening of the envelope to divide the envelope into two non-communicating chambers, electrodes in each chamber, a body of mercury in each chamber and a single sealing tip on the envelope.

5. A mercury switch comprising an envelope, a partition dividing the envelope into two non-communicating chambers, said partition being impervious to mercury but being pervious to gas, a single sealing tip directly communicating with one of said compartments and communicating with the other of said compartments through said partition, electrodes in each of said chambers, a hard glass tube in each chamber, a rin of ashestos supporting each hard glass tu e and dividing each chamber into two compartments, one of the electrodes extending into the hard glass tube and the other electrode extending in between the hard glass tube and the soft glass envelope, and a body of mercury in each chamber immersing the electrodes thereof and bridging same in one position of the 5 switch, the body of mercury dividing into two portions, one in each of said compart ments, in another position of the switch the portions of the mercury uniting and separating as the switch is operated within the hard glass tube.

6. A mercury switch comprising an envelope, an asbestos partition of such size and shape as to completely block the internal opening of the envelope, said asbestos partition being positioned in the envelope to divide the envelope into two electrically separated chambers, said asbestos partition being made up of asbestos tape wound to provide a substantially solid structure and cemented to the envelope.

7. A mercury switch of the character described comprising an outer envelope, a perous partition dividing the envelope into two electrically separated chambers and means in each chamber providing a mercury switch unit.

8. A mercury switch of the character described comprising an outer envelope, means separating the envelope into two electrically isolated compartments while permitting the transfer of air and gas from one compartment to the other and means in each compartmentproviding a mercury switch unit.

9. mercury switch comprising an en- 3 velope having two bodies of mercury therein,

electrodes cooperablewith each body of mercury to rovide separate switch units, and a barrier etween and isolating said bodies of mercury and adapted to permit the flow of 1 40 air or gas theret-hrough.

In witness whereof, I hereto afiix my signature.

PAUL K. CRAIWBLET. 

